{
    let i = 55
    {
        let i = 3
        console.log(i)
        //全局变量相当于 var age = 22
        age = 22
    }
    console.log(i)
}

const ADDR = '河南省郑州市科学大道'
console.log(age)
console.log(ADDR,Math.PI)
